Heretofore, photosensitive resin compositions have been used to prepare masks for production of circuits, such as semiconductor integrated circuits (IC) and thin film transistor (TFT) circuits for liquid crystal displays (LCD), and a photosensitive resin composition capable of forming a finer pattern structure, is required.
On the other hand, a photosensitive resin composition has attracted attention also as a resist material to form ITO electrodes for LCD, an organic EL display, etc., or as a permanent film-forming material for an interlayer insulation film, a circuit-protecting film, a barrier rib material for a color filter, a barrier rib material for an organic EL display, etc. For example, in the production of a color filter, an ink jet method has been proposed wherein ink is applied by ink jet within fine pixels, but formation of a pixel pattern is carried out by photolithography using a photosensitive resin composition, wherein a coating film cured product of the photosensitive resin composition is utilized as barrier ribs between pixels.
In the ink jet method, in order to prevent e.g. color mixing of inks between adjacent pixels, barrier ribs are required to have so-called ink repellency i.e. repellency against the ink solvent such as water or an organic solvent. Further, the barrier ribs are required to have “ink falling property” so that ink sprayed on barrier ribs as slightly deviated from pixels will fall into the desired pixels.
Further, in order to inject plural inks and apply them separately in each pixel, barrier ribs are required to have “durability of ink repellency/ink falling property” i.e. a nature to maintain ink repellency and ink falling property even after applying one ink solvent.
Further, after forming barrier ribs for a pixel pattern via a photolithography step by applying a photosensitive resin composition, stain on the substrate surface in pixels may sometimes be removed before injecting inks. For example, a step of cleaning the substrate surface by e.g. irradiation with a low pressure mercury lamp or with ultraviolet rays such as excimer UV, or by photo-ashing treatment (hereinafter referred to as a cleaning step) may be mentioned. Barrier ribs are required to have a nature to maintain the ink repellency and ink falling property even after such a cleaning step, i.e. “ink repellency/ink falling property after UV irradiation”.
JP-A-8-176504 (claim 1) discloses a coating agent which comprises a copolymer (component 1) having (meth)acryloyl groups, of a structure wherein an isocyanate group of an isocyanate group- and (meth)acryloyl group-containing monomer is addition-reacted with hydroxyl groups of a polymer obtained by reacting a perfluoroalkyl group-containing α,β-unsaturated monomer, a polysiloxane chain-containing α,β-unsaturated monomer and a hydroxyl group-containing α,β-unsaturated monomer as essential components, and a hydrocarbon type monomer (component 2) containing either a (meth)acryloyl group or a vinyl group in its molecule.
JP-A-11-279243 (claim 4, paragraph 0035) discloses a composition which comprises an ultraviolet-curable resin (component 3) formed from a copolymer of an unsaturated monomer component containing an ethylenically unsaturated monomer having silicon atoms and having at least two ethylenically unsaturated groups, carboxyl groups and silicon atoms per molecule, an epoxy compound (component 4) having at least two epoxy groups per molecule, a photopolymerization initiator (component 5), a diluting agent (component 6) and a leveling agent (component 7) such as a fluorine type surfactant.
However, with the hydrocarbon type monomer in the coating agent disclosed in JP-A-8-176504 (claim 1), it has been difficult to have a difference in alkali solubility between an exposed portion and a non-exposed portion, and from such a coating agent, it has been difficult to form a fine pattern. On the other hand, the leveling agent such as a fluorine type surfactant disclosed in JP-A-11-279243 (claim 4, paragraph 0035), has no photosensitive group, and such a composition was inadequate in the durability of ink repellency.